Influence of low-level laser radiation on the physico-chemical indicators of biomembranes

Bone regeneration is a desired treatment outcome in implant dentistry. The primary goal of the current investigation was to assess the joint effect of low-level laser therapy (LLLT) and leukocyte- and platelet-rich fibrin (PRF) on new bone formation. During this experiment study, forty bone defects (8 mm in diameter) were generated in the calvaria of ten New-Zealand white rabbits. defects were filled with autogenous bone defined as the control group, autogenous bone with leukocyte- and PRF (PRF group), autogenous bone and low-level diode laser radiation (LLLT group), and autogenous bone with leukocyte- and PRF and low-level laser radiation (LP group). Laser irradiation was done every second day for 2 weeks after surgery. Five rabbits were randomly selected to be sacrificed on postoperative weeks 4 and 8. On one and two-month post-surgery, histological and histomorphometric parameters including bone formation, fibroblast, and osteoblast were assessed. The histological panel depicted that the ratio of fresh bone formation increased at one-and two-month postsurgery in all treatment groups compared to the control group. The most favorable results were seen in the LP group, followed by the PRF group. Based on the ANOVA test, bone neoformation was statistically significant in the LP group in comparison with the control group (P<0.001). One-month post-surgery, a higher degree of fibroblast was seen in the control group, while the last place was for LP group (118.6 ± 6.9 vs. 24.0 ± 3.2). In the PRF group, the percentage of bone formation was higher than that in the control group (13.2 ± 2.8 vs. 2.0 ± 1.2), but no significant difference when compared to the LP group (13.2 ± 2.8 vs. 19.0 ±.3.8). The combined L-PRF and LLLT was more likely to have a positive effect on accelerating bone regeneration and reducing fibrosis.

In this paper the results of an experimental-clinical study substantiating the use of low level laser radiation (LLLR) at certain wavelengths for treatment of cancer patients are given. In the first part of this study, with animal experiments, laser action parameters providing reliable renewal and regeneration stimulation are selected. It is shown that, under the effect of LLLR, the speed and quality of regeneration in wounds after tumor removal are changed as well as the intensity of dissemination and tumor growth. A change also occurs in the functional properties of lymphocytes, which have immunological control in the organism. On the basis of the experimental data obtained, the contingent of cancer patients for whom LLLR can be recommended was determined.

Introduction. Psoriasis is a typical complex multigenic and multifactorial disease with heterogeneous genetic heredity, which requires the interaction of genes both with each other and with environmental factors. STAT3 (Signal Transducer and Activator of Transcription 3) has only recently been considered a key player in the development and pathogenesis of psoriasis and psoriatic inflammatory conditions.Aim of the study. To study the expression of the STAT3 gene in the affected part of the skin of psoriasis patients in relation to the visually unaffected part. To study the change in the STAT3 gene expression level in psoriasis-affected skin as compared to nonaffected skin in patients before and after treatment with low-level laser radiation at a wavelength of 1.27 pm.Materials and methods. The study involved 12 psoriasis patients. Biopsies from the unaffected skin were taken at a distance of about 3 cm from the affected skin. Real-time PCR analysis was performed.Results and discussion. The expression of the STAT3 gene was quantitatively measured using RT-PCR in the affected part of the skin of psoriasis patients compared to the visually unaffected part of the skin of the same patients before and after treatment with low-level laser radiation with a wavelength of 1.27 gm (short-wave infrared). As a result of the study, an increase in the expression of the STAT3 gene in the affected part of the skin of psoriasis patients of an average of 3.96 ± 2 times was experimentally shown. A decrease in gene expression was observed in psoriasis affected skin compared to samples of non-affected areas. After treatment of patients with low-level laser radiation, a significant reduction in the expression of the overexpressed STAT3 gene to 1.75 ± 0.5 times was observed.Conclusions. The transcription activity of the STAT3 gene can be an indicator of the efficacy of psoriasis treatment at the molecular level and can also be a new therapeutic target.

Introduction. PPARγ is the most studied PPAR subtype and is expressed predominantly in adipose tissue, heart, colon, kidney, spleen, intestine, skeletal muscle, liver, macrophages, and skin. In the skin, PPARγ controls the genetic regulation of gene network expression involved in cell proliferation, differentiation, and inflammatory responses. PPARγ (Peroxisome proliferator-activated receptor gamma) has only recently come to be considered a key player in the development and pathogenesis of psoriasis and psoriatic inflammatory conditions.Aim of the study. To study PPARγ gene expression in the affected skin of psoriasis patients in comparison with visually unaffected skin. To study changes in PPARγ gene expression level in psoriasis affected skin in comparison with unaffected skin in patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm.Materials and methods. Twelve patients with psoriasis participated in the study. Biopsies from unaffected skin areas were taken at a distance of about 3 cm from the affected skin. Analysis was performed by real-time PCR.Results and Discussion. We quantitatively measured PPARγ gene expression using RT-PCR in the affected skin of patients with psoriasis in comparison with visually unaffected skin in the same patients before and after treatment with low-level laser radiation with a wavelength of 1.27 μm (the short-wave part of the infrared range). The study experimentally showed a 1.3 ± 0.27-fold decrease in PPARγ gene expression in the affected skin of psoriasis patients on average. Significant increase in over-expression of PPARγ gene up to 2,13 ± 0,47 times was observed after treatment of patients with low-level laser radiation.Conclusions. PPARγ gene expression may be an indicator of the efficacy of psoriasis treatment at the molecular level, as well as become a new therapeutic target.

The objective of this study was to compare the efficacy of fluoride varnish (Fluorniz(r)) and irradiation with a gallium-arsenide-aluminum diode laser in the treatment of cervical dentin hypersensitivity. Cervical dentin hypersensitivity (CDH) is a painful condition that is highly prevalent in the world's adult population, with one in six patients presenting this symptom. Eighty-six teeth were divided into two groups: Group 1, teeth treated with Fluorniz; Group 2, teeth irradiated with a GaAlAs laser at a 4 J/cm2 dose. The two treatments were applied to the buccal cervical region in four sessions, at intervals of 72 to 96 h. The response of the patient to tactile and thermal-evaporative stimuli was rated on a visual analog scale. The results showed a reduction of hypersensitivity in response to tactile and thermal-evaporative stimulation at the end of treatment in both groups. In conclusion, short-term treatment with Fluorniz was found to be more effective than low-level laser radiation in reducing cervical dentin hypersensitivity.

The purpose of this study was to investigate the in vitro effects of low-level laser radiation (LLLR) on some rheological factors of the human blood, such as complete blood count (CBC) parameters and blood sedimentation rate (BSR). We were mainly concerned with the alterations caused by LLLR action on blood cells (erythrocytes and leukocytes) of fresh blood obtained from apparently healthy adult patients. We used low doses ranging between 0.80 J x cm(-3) and 4.40 J x cm(-3), at the very low-power densities of the laser radiation, so as not to damage the cell structure and not to alter in an undesired manner their functions. Blood samples were taken from 22 volunteers. Where health problems existed, they were indicated for each case. The parameters mentioned above were measured before (control samples) and after irradiation. A He-Ne laser, operating in continuous wave, as a radiation source (632.8 nm, 1 mW, intensity of 8 x 10(-2) W x sr(-1), mean power density incident on blood samples around 30 mW x cm(-2), beam spot diameter 2 mm) was used. The measurements were performed immediately after irradiation. Only the erythrocyte complex was irradiated. EDTA anticoagulant was used. The measurements using a computerized hemoanalyzer type SERONO showed significant differences between control and irradiated blood samples concerning the following parameters: RBC (in 22% of cases), HGB (47.3%), HCT (84.2%), RDW (11%), PLT (5.26%), MPV (33.3%), WBC (5.26%), MONO (26.3%), and GRAN (63.15%). In the case of BSR (44%), the significant differences were noticed especially in the cases of patients suffering from some acute or chronic diseases. Nonsignificant differences were noticed in the cases of MCV, MCH, MCHC, RDW, and LYMPH. This study has shown that LLLR, even though used at low doses and low power densities, produced some changes of the rheological factors of the blood, as follows: a revitalizing and regenerating effect on mitosis stimulation and a nondamaging and biostimulating effect on the cell membrane (by keeping unmodified MCV, MCH, and MCHC). In 3 cases out of 22, hemolysis (complete or partially) occurred, but we are not yet sure whether this was caused by laser exposure or by certain environmental physical factors.

This study investigated the in vitro effects of low-level laser radiation (LLLR) on selected rheologic constants of the human blood. The variations of CBC parameters to the received dose were determined, as well as of blood viscosity (an erythrocyte aggregation index), as a research method for some structural alteration of blood proteins. This was also confirmed by the electrophoretic study of plasma proteins from the irradiated blood. Fresh blood samples (whole blood) from 16 adult regular blood donors were irradiated with a He-Ne laser (lambda = 632.8 nm; power output = 6 mW; mean irradiance on blood samples approximately 180 mW.cm-2; beam spot diameter approximately 2 mm), operating in continuous wave. Doses ranged between 0 (control sample) and 9.346 J.cm-3.EDTA (for CBC and viscosity measurements) or citrate (for electrophoresis) anticoagulant was used. Measurements were performed before (control samples) and after irradiation. In most of the cases, the measurements were made immediately after irradiation. In some cases, the measurements were made after 24 or 48 h after irradiation, respectively, to conclude whether the modifications caused from irradiation occur in time, or immediately after irradiation. Following irradiation, marked variations of some erythrocyte and leukocyte indices and changes of the erythrocyte aggregation (viscosity), as a function of received dose, were observed. Significant differences between control and irradiated blood samples were found for the following rheologic factors: RBC (in 22.2% of cases); HGB (26.8%); HCT (82.4%); MONO and GRAN (36.7%); viscosity (82.5%). From the plasma proteins: albumin (22.2%); alpha 1 globulin and gamma globulin (18.5%); fibrinogen (70.4%). In most of the cases, remarkable effects (maxima) were noticed around 1.2 J.cm-3 dose value. We consider this dose value as optimal, one that can lead to beneficial effects. The cell membrane integrity was not affected from irradiation, for doses between 0 and 9.346 J.cm-3, and will probably not even be affected at higher doses (see MCV and MCHC behavior). The effect of LLLR on red blood cells confirms the nonresonant mechanism of this biostimulating effect, by the changes occurring in the cell membrane (in our case, blood cells), by revitalizing of red blood cell functional capacities and by several biochemical effects at the membrane's level. These are to be studied thoroughly in future studies. The physical-biochemical and biological effects caused by LLLR on blood can influence the physical-chemical parameters needed for the long-term storage of blood products. These effects can also lead to a quicker revitalization of the erythrocyte membrane (which was subjected to the action of some physical and biochemical factors during the preservation process), to perform its oxyphoric function in transfusion procedures.

The aim of this paper was to investigate the efficacy of low-level laser radiation (LLLR) with wavelength of 904 nm on the stimulation of the healing process of postoperative aseptic wounds (early scar). Low-level laser therapy (LLLT) has been increasingly used to treat many disorders, including wounds. However, despite such increased clinical usage, there is still controversy regarding the efficacy of this wound treatment in curent clinical practice. LLLT has been used to treat cutting plague in the right instep and on the left foot. Both resulted from sutured wounds. The clinical evaluation by semiquantitative methods is presented. Clinical evaluation showed that the healing process of these postoperatively treated wounds has occurred and that the functional recovery of the patients (i.e., return to their ordinary life) was faster than without treatment. LLLR with wavelength of 904 nm to stimulate postoperative aseptic wounds (early scar) is efficient in both cases of cutting plague.

Proper rheological properties of red blood cells (RBC) including flexibility and aggregability are essential for healthy blood microcirculation. Excessive RBC aggregation has been observed to be associated with many pathological conditions and is crucial in acute circulatory problems. Low-level laser radiation (LLLR) has been found to have positive effects on the rheology of human blood, however, the detailed mechanisms of blood photobiomodulation remains unclear. In this study, utilizing the single-cell technique optical tweezers (OT) and traditional light microscopy, the influence of photobiomodulation of human RBC was examined under different conditions of laser irradiation. The results revealed that high radiant exposure (over 170.5J/cm2 radiant fluence) caused enhanced RBC aggregation and cell shape transformation while the aggregation force between single RBC remained unchanged. LLLR with radiant fluence below 9.5J/cm2 by 450nm wavelength improved the RBC deformability, weakened the strength of cell-cell interaction in the RBC disaggregation process, and showed rejuvenating effects on RBC suspended in a harsh cell environment.

The purpose of this research was to investigate the influence of low-level laser radiation on erythrocyte membranes. The method of seif-hemolysis test of erythrocyte was employed in the research. Blood is taken from the vein of a healthy human. The blood was diluted by physiological salt water. Samples ofthe blood are divided into laser groups and control groups. Each sample of the blood was of 2m1 in volume and was put in a test tube. Each test tube of laser groups was radiated by He-Ne laser for about 40 minutes. The output power of laser vary from 1 mW to 8mW for different test tubes. After the laser radiation, the sample of the blood in test tubes was kept in 37CC for 24 hours, and then was tested for the haemolytic ratio. The result of the research showed that the haemolytic ratio of erythrocyte of laser groups was slightly larger than that of the control groups, and the bigger of the laser power, the larger of the haemolytic ratio of erythrocyte. This result indicates that the low-level laser radiation on blood can influence the membranes of red blood cell. This influence can be a stimulation to red blood cells. It can improve the membranous property and functions of red blood cell under some conditions. This result would be helpful to understand the mechanisms of the Intravascular Low-Level Laser Irradiation Therapy (ILLLIT).

The aim of the study was to evaluate the different frequencies of low-level laser radiation (diode - 670 nm and Helium-Neon632.8 nm) on healing process after human molar extractions. Frequencies of 5 Hz, 292 Hz and 9000 Hz were used in experiments. Monitoring ofsecretory IgA (sIgA) and albumin level in saliva and changes in bone density were used as objectivemarkers of biostimulatory effect. Subjective evaluation of therapy was observed using scale (from negative therapeutic effect;++++ excellent treatment effect). Changes of sIgA, albumin levels and bone density were compared in group of 1 50 patients (non-laser therapy - 30 patients). Differences in levels of the saliva markers (sIgA and albumin) were found to be significantcomparing irradiated and non-irradiated groups, as well as comparing groups irradiated by various modulatory frequencies. Itwas observed significant differences between increase of sigA res. albumin and subjective treatment feelings. Bone density afterextraction and six-months after surgical treatment was examined using the dental digital radiovisiography. There were detectedno significant differences between bone density in irradiated and non-irradiated groups perhaps due to our used therapy diagram.Keywords: dentistry, low-level laser radiation, secretory IgA, albumin,

Background: The problem of protecting and maintaining health of workers in the microelectronics industry exposed to adverse occupational factors including tension and overstrain of the muscles of the upper extremities and visual strain, gains special relevance. Objective: Introduction of the developed and patented low-level laser therapy techniques to recover functions of vision and the musculoskeletal system impaired in the course of work. Materials and methods: The study involved 65 chip assemblers aged 26–41 years. Their eyes, the back of the hands, and the collar area were exposed to low-level laser radiation from the red region of the spectrum. All employees were examined by a neurologist and a surgeon and their working conditions were evaluated. The accommodation apparatus was tested using an AKA-01 type accommodation meter. Results: After five 10-minute sessions, we registered an increase in the volume of absolute accommodation during the observation period before and after the work shift by 28 % and 19 %, respectively. On subsequent days of observation, we noted an increase in the accommodation during 10 days, followed by a decrease by the 30th day of observation. Application of preventive techniques helped eliminate spinal cord disorders in all workers. Blood circulation in fingers increased by 66 % compared to the initial condition. Discussion: Low-level laser therapy improves blood supply, intensifies redox processes in the retina of the eye, skin cells, and blood vessels. Conclusions: Low-level laser radiation of the red region of the spectrum relieves the spasm of accommodation and normalizes the efficiency of the accommodation apparatus. Such laser therapy helps eliminate spinal cord disorders and improve blood circulation. Introduction of the developed techniques can prevent occupational diseases and reduce disability in patients.

Repair of peripheral nerve injury is an important topic in the field of neural tissue rehabilitation research.At present there are many new technologies that can realize the treatment of peripheral nerve injury.As the research on the effect of laser radiation on biological mechanism develops,a new method for tissue regeneration is applied to the field of nerve injury repair.This paper is mainly centered on the recovery mechanism of low-level laser radiation,the function recovery after peripheral nerve injury and nerve tissue scarring inhibition.The new progress of laser treatment and nerve injury repair are reviewed. Key words: Low-level laser; Peripheral nerve; Scar tissue; Nerve regeneration

We investigated the influence of carrier systems for different commercially available water-soluble formulations for coenzyme Q10 on structural changes of model lipid membranes formed by 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and by a mixture of phosphatidylcholine and sphingomyelin (2.4:1). Structural changes in the membranes were measured using fluorescence anisotropy, electron paramagnetic resonance, and differential scanning calorimetry. Two fluorophores and two spin probes were used to monitor membrane characteristics close to the water-lipid interface and in the middle of the bilayer of the model lipid membranes. Different water-soluble carrier systems were tested. These data show that different systems can facilitate penetration of CoQ10 in the lipid membranes, where an increase in the lipid order parameter was observed. In addition, water soluble CoQ10 formulations better protect lipids from oxidation in liposome solution. With the exception of the carriers in an emulsified formulation of CoQ10, those in the other samples did not have any significant effects on membrane fluidity.

The study investigated the effects of low-level laser radiation and epidermal growth factor (EGF) on adult adipose-derived stem cells (ADSCs) isolated from human adipose tissue. Isolated cells were cultured to semi-confluence, and the monolayers of ADSCs were exposed to low-level laser at 5 J/cm(2) using 636 nm diode laser. Cell viability and proliferation were monitored using adenosine triphosphate (ATP) luminescence and optical density at 0 h, 24 h and 48 h after irradiation. Application of low-level laser irradiation at 5 J/cm(2) on human ADSCs cultured with EGF increased the viability and proliferation of these cells. The results indicate that low-level laser irradiation in combination with EGF enhances the proliferation and maintenance of ADSCs in vitro.